Device for extinguishing the flame and deadening the noise of the exhaust gases in internal combustion engines



Aug. 2, 1938. I BQYSEN 2,125,712

DEVICE FOR EXTINGUISHING THE FLAME AND DEADENING THE NOISE OF THE EXHAUST GASES IN INTERNAL COMBUSTION ENGINES Filed May 4, 1937 Unrmfor Patented Aug. 2, 1938 DEVICE FOR, EXTINGUISHING THE FLAME AND DEADENING THE NOISE OF THE EX- HAUST GASES IN INTERNAL CO1V$UTIGN ENGINES Friedrich Boyseri,

Stuttgart Heumadeu,

Ger-

many, assignor to the firm ll. Eberspacher 61. m. I). Hi, Esslingen-on-the-Neckar, Germany Application May l, 1937, Serial No. 140,995 In Germany May 2, 1936 4 Claims.

This invention relates to a device for extinguishing the fierce and deadeningthe noise of the exhaustgases in internal combustion engines.

For this puroose it has been proposed to sub- 5 ject the eiiiaust gases to strong cooling down. as, for instance, by conducting cooling-pipes through the chamber into which the exhaust gases after leaving the cylinders are passed, or by surrounding the said chamber by a coolw lug-jacket. The coolirigmedium may be a gas or a liquid. in motor cars and especially in air craft mostly the draft of air or in some cases also water is used for this purpose.

Furthermore it is well known to promote the transmission of heat through the walls of the cooling lines or through the outer jacket of the exhaust chamber by corrugating the said walls. This method of cooling is imperfect in as much as for obtaining a satisfactory result large surfaces would he required as well for doing away with the exhaust flames as for deadening the exhaust noise, whereby the weight and the cost would he increased to such an extent that this method is esoecially excluded in connection wit airplane motors.

According to the present invention the cham her, into which the exhaust gases coming from the cylinders are passed, is traversed by lines through which gaseous or liquid cooling media so are conducted and which are so arranged that at the sometime, besides the cooling action, deadening of the gas oscillations by molecular friction and rerlexion is obtained, the exhaust gases being farther compelled in a direction opposed to the direction of transmission of the sound waves in the exhaust gas.

The invention is illustrated by way of exampie in the annexed drawing of which Fig. l is a vertical cross-section and go Fig.2 is an elevation of an exhaust box.

The exhaust gases enter the chambers surrounded by a jaclzet c by an inlet pipe a. The jacket 0 is streamlined to'ofier the least possible resistance to the cooling medium flowing in the 45 direction of the arrow l. Within the chamber is are arranged-channels at extending parallelly to the longitudinal axis which channels are traversecl by the cooling medium. The slots e left free between the difierent channels conduct the exso haust gases, opposite their initial direction of 'flow, to the channel 1 left 'free inside the channels d. In the channel f the gases flow off to the rear end of the deadenirig device where they escape through the opening g into the open 55 air.

($11. loll-5%) By this particular arrangement of the channels e a double effect is obtained in view of the sound-deadening. The sound waves taken along in the direction of the gases flowing in the inlet pipes at can only enter the channels e after 5 reflexion at the inner surface of the jacket 0. Also in these channels owing to their curvatures again a multiple reiiexion of the gas oscillations (arriving as it is only reflected) takes place, so that no other oscillation. can reach the inner 19 channel f such which have been twice subjectecl to repeated reiieidon and thereby satis= iactorily deacleued. Gwing to the molecular frictime resulting from the flowing in these channels, and hesioles to the strong cooling down simultais rieously obtained by the cooling medium flowing in the channels at, an intensive deadening of oscillations is additionally eiiected in each of the partial gas currents which are, in accordance with the shape of the channels, very flat. Fur- 2o therrncre a cooling is eidected on the outer jacket 0. Therefore the entire effect of the device forming the oloiect oi the present invention-consisting in a perfect suppression of the exhaust flames combined with high-grade deadening of the os- 25 clllati-ons is obtained by the combination of a for extending refiexlon and an intense reduction of the enerey of the exhaust gases owing to molecular friction and cooling-down.

The aloovedescriloed contrivance slmultane- 3o ously entails an essential technical progress in consequence of the fact that the inner parts of the device are no more permanently exposed to high temperatures as they were in the devices hitherto used. Hereby the life of these parts 5 and therewith that of the entire contrivance is considerably increased.

l. A device for doing away with the exhaust flames and deadening the oscillations in the ex- 40 liaust gases of internal combustion engines. comprising a casing, spaced. cooling ducts longitudinally passing therethrough and dividing the interior of the easing into an inner tubular and an outer annular channel, an inlet for the exhaust gases entering the side of the device near one end ancldischarging tangentially into the said outer channel, and an outlet at the other end oi the casing, the spaces between the cooling ducts diverging from the way of the, gases iii the annular channel at an acute angle in backward direction.

2. A device for doing away with the exhaust flames and deadening the oscillations in the ex-, haust gases of internal combustion engines, comprising a casing. spaced curved cooling ducts lon-' gitudinally passing therethrough and dividing the interior of the easing into an inner tubular and an outer annular channel, an inlet for the exhaust gases entering the side ,of the device near one end and discharging tangentially into the said outer channel, and an outlet at the other end of the casing, the spaces between the cooling ducts diverging from the way of the gases in the annular channel at an acute angle in backward direction.

3. A device for doing away with the exhaust flames and deadening the oscillations in the exhaust gases of internal combustion engines, comprising a streamlined casing, spaced cooling ducts longitudinally passing therethrough and dividing the interior of the easing into an inner tubular and an outer annular channel, an inlet for the exhaust gases entering the side of the device near one end and discharging tangentially into the said outer channel, and an outlet at tae other end of the casing, the spaces between the cooling ducts diverging from the way of the gases in the annular channel at an acute angle in backward direction.

4. A device for doing away with the exhaust flames and deadening the oscillationsin the exhaust gases of internal combustion engines, com prising a streamlined casing, spaced curved cooling ducts longitudinally passing therethrough and dividing the interior of the casing into an inner tubular and an outer annular channel, an inlet for the exhaust gases entering the side of the device near one end and discharging tangentially into the said outer channel, and an outlet at the other end of the casing, the spaces between the cooling ducts diverging from the way of the gases in the annular channel at an acute angle in backward direction.

FRIEDRICH BOYSEN. 

